How far off are Zillow's estimates?

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Admiral
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How far off are Zillow's estimates?

Post by Admiral » Tue Aug 01, 2017 6:13 pm

I know the answer is probably "pretty far" but I'm wondering just how far...?

The Zillow market report for my zip code indicates the median list price is about $515/sq ft. (They don't break down the actual sold price, only the median list price of properties for sale, and the median list price per square foot.)

While this is probably high, typically most homes in my zip do sell for close to list price...which means it's not that high.

My home was appraised about a year ago (for a refinance) and the valuation was not even close to $515/sq ft. Closer to $375 sq ft.

Something is off, somewhere. I'm curious to know if anyone who has recently bought or sold has discovered what Zillow's margin of error is.

livesoft
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Re: How far off are Zillow's estimates?

Post by livesoft » Tue Aug 01, 2017 6:25 pm

Your appraisal should have listed the details about the comps used, so you can compare those sales prices to zillow yourself.
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curmudgeon
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Re: How far off are Zillow's estimates?

Post by curmudgeon » Tue Aug 01, 2017 6:28 pm

Zillow or other automated price estimators are most accurate within a neighborhood of very similar type/age houses. They still don't deal with specific upgrades or features, but those are typically of limited significance. When you have a much broader range of houses, in terms of types, ages, conditions, schools, etc, then the estimators are pretty useless.

If you care to understand your realistic values, then occasionally going to open houses in your area and later watching to see what those houses actually sell for (asking prices aren't always a good reference) will give you a better idea.

avalpert
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Re: How far off are Zillow's estimates?

Post by avalpert » Tue Aug 01, 2017 6:28 pm

I would suspect their 'median list price' is accurate since that is pulling from known data. There home value estimates are certainly off, my hunch is the factor is so volatile as to not be helpful.

As for your own appraisal - it should include both comps and detailed workup of the home itself so you should be able to get a sense for what separates your home from others.

ianferrel
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Re: How far off are Zillow's estimates?

Post by ianferrel » Tue Aug 01, 2017 6:32 pm

Note that if you're looking at zillow's estimate "chart", what they show you is their current estimation of past values, not a record of their past estimates.

I bought in Dec. 2015.

At the time, Zillow estimated the value of my house at around 4-5% over what we paid for it (their valuation was very close to what it was originally offered at. The previous owners lowered their price after about a month, and we bought it at pretty close to their new asking price).

Six months ago (a bit over a year after we bought), Zillow claimed that our home value was 14.5% higher than our purchase price.

Today, it estimates the value at 13% higher than purchase (and it now thinks that it was worth 6.5% more 6 months ago)

I believe that all of these estimations are a bit higher than they ought to be, but they're not terrible. But that's just for my house. I've definitely seen a few where the estimate was way off.

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Re: How far off are Zillow's estimates?

Post by cadreamer2015 » Tue Aug 01, 2017 6:35 pm

Zillow's estimates are reasonably good for what they are: a computer algorithm based on the publicly available data on the homes in your neighborhood. In my experience they are better for suburban tracts where all the homes are more or less alike, with several different models. Less good for unique homes, historic homes, etc. Zillow's own data show that their median error is about 5% or less in many markets. But if you want to have a 90% confidence interval, in many markets that is the Zestimate +/- 20%.

Price per square foot is actually a pretty poor metric for home values. In many higher priced markets there is a lot value and a value of the physical home. Conflating everything into $/square foot of house is misleading. A buildable lot in the SF Bay area might be worth $1 Million. If there's a 900 square foot teardown home on that lot, does it make sense to say that the value of the home is $1,100 per square foot? Not really.
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retiredjg
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Re: How far off are Zillow's estimates?

Post by retiredjg » Tue Aug 01, 2017 6:38 pm

In my experience in selling my own home, Zillow can be right on the money or just flat out wrong. I think Zillow information can be helpful sometimes, but I would not depend on it for anything that matters.

dreamjob9
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Re: How far off are Zillow's estimates?

Post by dreamjob9 » Tue Aug 01, 2017 6:40 pm

Admiral wrote:I know the answer is probably "pretty far" but I'm wondering just how far...?

The Zillow market report for my zip code indicates the median list price is about $515/sq ft. (They don't break down the actual sold price, only the median list price of properties for sale, and the median list price per square foot.)

While this is probably high, typically most homes in my zip do sell for close to list price...which means it's not that high.

My home was appraised about a year ago (for a refinance) and the valuation was not even close to $515/sq ft. Closer to $375 sq ft.

Something is off, somewhere. I'm curious to know if anyone who has recently bought or sold has discovered what Zillow's margin of error is.

I have found REDFIN estimate to be highly accurate. Much better than Zillow! Imho

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celia
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Re: How far off are Zillow's estimates?

Post by celia » Tue Aug 01, 2017 6:57 pm

Admiral wrote:My home was appraised about a year ago (for a refinance) and the valuation was not even close to $515/sq ft. Closer to $375 sq ft.
But when you bought it, you likely bought the land too. Did the home appraisal only calculate the rebuilding costs or did it include the land?

I think Zillow's estimate for our house is quite low, because there are no recent public records/building permits/sales listed for it. I like it that way. We've lived here over 30 years and are paid off.

corysold
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Re: How far off are Zillow's estimates?

Post by corysold » Tue Aug 01, 2017 7:04 pm

Zillow fluctuates quite a bit. Our home went from an estimate near the purchase price, to +$120,000 in 9 months. Then, one day, it went to $10,000 under purchase price, where it has been for a few months. The worrying thing to me, is that the increase is reflected nowhere in the past data. So it is as if it never happened.

I understand it is just a tool and an estimation, but the whole process seems muddled and confusing with nothing to back the numbers they are putting out there.

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Re: How far off are Zillow's estimates?

Post by blueblock » Tue Aug 01, 2017 7:06 pm


Alan S.
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Re: How far off are Zillow's estimates?

Post by Alan S. » Tue Aug 01, 2017 7:09 pm

For a large tract, particularly of cookie cutter homes where there are a lot of comps, Zillow should be reasonably accurate.

For custom homes on the other hand, not knowing much of the details in each particular home and with few comps, they could be way off. So it depends.

Have a neighbor with a home with a shop on the lower level with attached bath. Owner changed Zillow input to call the shop a 4th bedroom and the zestimate immediately went up 40k. The owner changed nothing about this space other than the description. No one would want to have this space as their bedroom, so the reckoning will take place when he lists the home.

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Re: How far off are Zillow's estimates?

Post by Van-Guard23 » Tue Aug 01, 2017 7:20 pm

I use Zillow for estimating our house's value as part of our net worth calculations. I would normally compare values on Zillow, Redfin and Realtor.com and while the values on Zillow and Realtor.com are quite close to each other, Redfin's figures are about 9% above the other two. I just use whatever is lowest.
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Re: How far off are Zillow's estimates?

Post by bighatnohorse » Tue Aug 01, 2017 7:36 pm

In my particular case, Zillow looked at the first page of the local assessor website. Zillow missed the 2nd page of the assessor's website which shows my shop building with 200 amp service and 4-bedroom septic. The Zillow algorithm failed in that case.

My double wide trailer home in the Southwest on one acre and is surrounded by 450K and higher priced homes. There's no way Zillow can fathom what that place is "worth".
Zillow has to have like-kind home in the vicinity to be near accurate.

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Re: How far off are Zillow's estimates?

Post by abner kravitz » Tue Aug 01, 2017 7:56 pm

The Zillow estimate for my home is not even 50% of its market value. This is not a prejudiced homeowner speaking - I base this on 2 recent appraisals, the tax assessment, and every sale in my neighborhood in the last 3 years. I don't really care, but it could be an irritant if I wanted to sell.

cookieid
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Re: How far off are Zillow's estimates?

Post by cookieid » Tue Aug 01, 2017 8:15 pm

My house is a single family home with about 2000 sq ft finished but it says townhouse with about half of sq ft. For sure it is off and I ignore their estimate .

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Re: How far off are Zillow's estimates?

Post by Grt2bOutdoors » Tue Aug 01, 2017 8:26 pm

Way off. Expanded sq footage of home yet zillow does not reflect it. Zillow is useless.
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Re: How far off are Zillow's estimates?

Post by Jack FFR1846 » Tue Aug 01, 2017 8:56 pm

I don't know if my house value is on or off. Looking at my house specs, the year built was off by a year, the last purchase date was off by a year, the square footage was off by 100.
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Re: How far off are Zillow's estimates?

Post by madbrain » Tue Aug 01, 2017 9:16 pm

I had my Zestimate change recently by $400,000 from one week to the next. I wouldn't trust it one bit.

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Re: How far off are Zillow's estimates?

Post by RobLIC » Tue Aug 01, 2017 10:59 pm

I live in a HCOL part of Queens, N.Y. High-end studio. Zillow estimate swung by over $300K in last week alone. I'm not looking to sell, but seems to me it could only cause bad feelings on one side or the other. Not ready for prime time.

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Re: How far off are Zillow's estimates?

Post by DVMResident » Tue Aug 01, 2017 11:05 pm

As other's have pointed out, the Zillow estimates swing wildly and can miss the mark by a wide margin (+65% of the house we're in right now).

I do find value in Zillow for finding comps. You can make a fairly good estimate yourself from recent sales and comparing to similar homes.

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Re: How far off are Zillow's estimates?

Post by dave_k » Tue Aug 01, 2017 11:26 pm

Over the last few years it's gone from overvaluing our primary home to undervaluing it, and now back to overvaluing it (a 50% swing just in the last year). I think it has trouble because it's waterfront but near a lot of non-waterfront homes in neighborhoods that vary, and the comps it uses are literally all over the map.

We also have a secondary waterfront home that it has consistently overvalued. That area has a larger proportion of expensive waterfront homes. In both cases the houses are small and old, with the land value being far more than the structure value. I think it has a more difficult time with that scenario.

I logged in and updated some details for both properties (including increased square footage for one), and even though I left the comps alone it gave me a "private" estimate in both cases that is more realistic, but maybe a bit high still in both cases (although I'd like to believe them, I'm not quite that optimistic).

I too think it's good for finding comps yourself and estimating it that way. That can still be problematic though if it's got the details wrong on the "recently sold" properties.

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Re: How far off are Zillow's estimates?

Post by Pajamas » Tue Aug 01, 2017 11:28 pm

Some Zillow estimates are exactly right, or as close as an estimate could be. Others are off by a little and many are off by a lot. Furthermore, housing values fluctuate. There is no way to tell how accurate a particular estimate is. Even when you have a good appraisal done by a qualified appraiser, with a detailed analysis based on good comps, you might get more or less for a property when you actually sell it. Those "Zestimates" are basically a marketing tool.

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Admiral
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Re: How far off are Zillow's estimates?

Post by Admiral » Wed Aug 02, 2017 6:34 am

Thanks all for replies. The comps we had with appraisal were not really comparable (in same zip, but not historic like ours) so it was inaccurate in my opinion.

What I find odd is that data is (are?) data. The median list price is the median list price, assuming they are properly scraping the data from the MLS. So, that SEEMS like it should be pretty accurate, at least in terms of what houses are being listed for. Granted, there are a number of high-end (1.5m and above) new homes that may be distorting the list prices a bit/skewing more expensive.

What I don't get is why they don't show the SOLD price. I am assuming this data is also publicly available. I wonder if it would show that their other data is inaccurate.

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Re: How far off are Zillow's estimates?

Post by mouses » Wed Aug 02, 2017 6:45 am

I think Zillow is useless. Just looking at the nearby homes in my neighborhood, what I know of the homes ages and interiors, what the local property tax database says, zillow just isn't accurate.

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Shackleton
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Re: How far off are Zillow's estimates?

Post by Shackleton » Wed Aug 02, 2017 7:06 am

Finally a topic right up my alley (data management)

First off, a median is just a midpoint so unless your house is THE median then that number is meaningless for calculating your value. Same with mean (average).

For all the people with houses where the data doesn't match reality, Zillow is pulling data from a disparate set of public or private (purchased data) sources, along with crowdsourced data (owner supplied) and matching it according to various matching rules, cleansing the data to remove anomolies, enriching the data, aggregating, integrating the data, etc. This is Master Data Management, and can be a challenge for any company, but a company like Zillow that has pretty much zero degree of control of the data coming in (meaning they can't control the data structure, data quality of the source systems, etc) has it much more challenging than a large bank or a company that generates the majority of their master data from their own systems. Once the data is in their MDM solution or a data warehouse, they do their super secret zillow zestimate which as others have pointed out is only as good as the data for the surrounding area. If a house is unique, or there are very few surrounding sales the zestimate will not be as good.

I believe it was Zillow a few months ago that was offering g a $1 million prize for any data scientist that could create a better zestimate. Unfortunately I'm not a data scientist but I do know that some of the ones at the megacorp where I work were spending some of their off hours working on it. So far, no one has been able to improve it to my knowledge.
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Re: How far off are Zillow's estimates?

Post by stan1 » Wed Aug 02, 2017 7:09 am

Zestimates are for entertainment purposes. Nothing more.

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teen persuasion
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Re: How far off are Zillow's estimates?

Post by teen persuasion » Wed Aug 02, 2017 7:13 am

Zillow is conflating different property info, confusing data.

The empty land next to our house went up for sale, and that data is mixed in with our home's history now, according to Zillow. It looks like our address sold for $12k last December, but it mentions our garage, our house built in 1880 (actually 1840s), our tax valuations, our purchase price 22 years ago. The acreage for the lot is correct, and the listing suggests building a dream house on the land, but it's completely jumbled together.

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Re: How far off are Zillow's estimates?

Post by Chadnudj » Wed Aug 02, 2017 7:19 am

I think it tends to vary in terms of accuracy based on your property's neighborhood/features....but it isn't TERRIBLE, per se.

I have two properties: our primary home condo and a rental property in another state. For our primary home, I use our purchase price as the value in my net worth spreadsheet, even though I'm certain our property's value has increased (the condo upstairs sold last year for a huge gain on what ours sold for and the condos are identical; other comps in the neighborhood with nearly identical features/square footage or inferior features/square footage have sold for significantly more than what we bought for) -- I figure that since we're using our home it's probably not smart to give a market-based value to it (since we won't be selling/accessing that equity increase until we decide to move), and better to be conservative in the estimate of that value.

On the rental property, I use the Zillow estimate. Yes, it's probably inaccurate. But like my portfolio of stocks and bonds, I don't need 100% accuracy in determining the value today because I'm not SELLING it today -- I just need a general idea of how I'm doing. Just like my stocks/bonds could go down 20% or more in a matter of months, so too could my house value swing drastically either as a result of Zillow errors or real world market fluctuations. Since all net worth calculations are just an estimate until I'm really close to NEEDING to know an accurate number, the Zillow estimate works fine for the rental property and a general gauge of how it's doing.

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Re: How far off are Zillow's estimates?

Post by Rupert » Wed Aug 02, 2017 7:26 am

Grt2bOutdoors wrote:Way off. Expanded sq footage of home yet zillow does not reflect it. Zillow is useless.
Is there any way Zillow could know that you expanded the square footage of the home? Is it reflected in public records anywhere? If not, then it's not really Zillow's fault. You can, as a homeowner, correct the information Zillow has about your home. They will take your word for it. Which is really another reason to be skeptical of Zestimates, isn't it? Moral of the story: Zillow is a useful tool but not a perfect tool when you are house hunting. Nevertheless, many home shoppers use it. So if you're going to list your house for sale, better check the Zestimate and update any inaccurate information.

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Admiral
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Re: How far off are Zillow's estimates?

Post by Admiral » Wed Aug 02, 2017 7:36 am

I just compared with Redfin. Their price per sq ft is even HIGHER.

I'm not selling, I too just use these sites for entertainment/to make myself feel good about my paper net worth.
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Re: How far off are Zillow's estimates?

Post by alfaspider » Wed Aug 02, 2017 8:10 am

Another vote for useless. My house has experienced 20%+ swings from month to month in an otherwise stable housing market. There's a ton of noise.

As others have mentioned, it probably works better in neighborhoods with a lot of similar houses. In an older neighborhood like mine where there is a mix of houses built from 1900s to present, with radically varying styles and construction, and with no two houses on the same floor plan, I think the algorithm just goes haywire.

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Re: How far off are Zillow's estimates?

Post by taguscove » Wed Aug 02, 2017 8:43 am

Speaking as a data scientist, I admire what Zillow is trying to do. They've fit a good model upon the best available data. However, realize that the data comes from multiple sources (mostly public) and is messy. Zestimate won't discover your kitchen renovation, basement addition. It may even get your square footage wrong if public sources are inconsistent. For a free product, Zestimate is as good as you'll get.

I wish they would provide confidence intervals with their estimates. Anecdotally, some people take the Zestimate too seriously instead of thinking of it as xxx prediction +/- 15%.

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just frank
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Re: How far off are Zillow's estimates?

Post by just frank » Wed Aug 02, 2017 9:15 am

If you really care, use Zillow to find several good comps (age/repair/streetview/etc) in your area, and then average the cost per square ft for those. Multiply by your square footage....and you should be close. I was within a few % beforehand when I had several appraisals/refis with this method.

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Re: How far off are Zillow's estimates?

Post by hightower » Wed Aug 02, 2017 9:18 am

Zillow posts it's own data on accuracy. It varies from city to city. Read up here: https://www.zillow.com/zestimate/

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Re: How far off are Zillow's estimates?

Post by bsteiner » Wed Aug 02, 2017 9:20 am

Sometimes they're close, but sometimes they're not.

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Re: How far off are Zillow's estimates?

Post by e5116 » Wed Aug 02, 2017 9:23 am

I agree with above that Zillow can range to pretty accurate to not even close, but I wouldn't say it's completely "worthless." It gives you a general magnitude based on specs. Obviously, as a smart human, you should take the number with a grain of salt and can examine comps on your own to come up with your own estimate. Basically, Zillow can only base its estimate on the information provided to the county records. If those are wrong, it's not Zillow's fault. I haven't seen any issue with data incongruencies between the county official records and Zillow pulling that information. (That is not the case with Zillow's pulling of GreatSchools data, which is very outdated in my neighborhood and needs a data refresh - but I also find GreatSchool's ratings terrible anyways).

Additionally, Zillow simply bases their estimates on the publicly available facts and has absolutely zero insights into how updated the interior is, other enhancements, etc. So, they look at square footage, the number of bedrooms, baths, garage, past sale prices, and put that into an algorithm that spits out a number. If you spend $80k on an update to a master bath and kitchen, Zillow doesn't care, but of course the market would if you actually put your house up for sale. Those improvements have added value. I find that Zillow is more of a "spec-based" estimate whereas Redfin is more of a "comp-based" estimate (using the house specs to adjust upward/downward based on nearby sales).

For my house, Zillow and Redfin estimates are actually within $10k surprisingly, when they've been as far as $100k apart in the past and both are actually reasonably accurate for my home AT THE MOMENT in my opinion, but that's by chance as it has varied widely. I have actually found Redfin's estimate to vary more widely than Zillow for my home as my area is challenging as every house is unique and varies greatly (so new sales can skew it one way or the other). The thing that is interesting that the house next to mine just sold a couple months and the Zestimate is $4k above the sale price, whereas the Redfin estimate is $80k above the sale price. Obviously, Zillow relies more heavily on sale price and other specs whereas Redfin is simply looking at comps. In that case, the Zestimate is much more accurate but YMMV.

It's a fun tool that is mostly marketing, but can have some limited value in certain circumstances. I find the most value in looking at how the area/zip code Zestimate has changed over time -- I think for a single house it's not as accruate, but for the neighborhood as a whole, it does trending reasonbly accurately since has far more inputs.

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Re: How far off are Zillow's estimates?

Post by cookieid » Wed Aug 02, 2017 9:24 am

My house is for sale and listed under mls. Zillow doesn't let me as a homeowner to correct the errors. I then contacted them requesting for correction but they ignored so I changed the status to sold for $1 hopping my listing wouldn't be shown there. I would rather have no listing there than have errors. The listing was gone for a few days then reappeared with the same errors. County record, Trulia, Redfin, Realtor.com and other sites show correct data.

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Re: How far off are Zillow's estimates?

Post by alfaspider » Wed Aug 02, 2017 9:24 am

hightower wrote:Zillow posts it's own data on accuracy. It varies from city to city. Read up here: https://www.zillow.com/zestimate/
Interesting. I note I am in a one-star city, so that may explain a lot of the inaccuracy.

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Re: How far off are Zillow's estimates?

Post by bluebolt » Wed Aug 02, 2017 9:37 am

Zillow itself says you should use other data when valuing homes. When I was looking for a house, it was useful for me as a data point in addition to the other comp research I did. I certainly wouldn't trust it on its own as a single data point. But, I wouldn't trust almost any other single data point either.

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Re: How far off are Zillow's estimates?

Post by vested1 » Wed Aug 02, 2017 9:56 am

Redfin estimates my home's value 4% above Zillow's estimate. Zillow seems to be trying to be more realistic in their estimates than they were in the past, which was far below what homes were selling for in our area. Zillow does provide valuable information on what's for sale, asking price and sold price however. I noticed that it converted all the homes on our block to 1 bedroom, even though they all have 2. I added details to our home's profile and the estimate has risen dramatically since then.

Of more concern to me are the appraisals given by banks, which seem to be vastly lower than actual value in order to manipulate loan agreements. I applied for a HELOC some years ago and Chase appraised our home about 200k below Zillow's already low estimate with a drive by appraisal. When I complained and cancelled the HELOC request out of disgust they sent us a letter saying we were denied due to a low credit rating. Our credit rating was then and continues to be in the 800's. There seems to be little recourse when dealing with banks who won't approve loans for prospective buyers due to an artificially low appraisal.

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Re: How far off are Zillow's estimates?

Post by Carefreeap » Wed Aug 02, 2017 10:42 am

Admiral wrote:I know the answer is probably "pretty far" but I'm wondering just how far...?

The Zillow market report for my zip code indicates the median list price is about $515/sq ft. (They don't break down the actual sold price, only the median list price of properties for sale, and the median list price per square foot.)

While this is probably high, typically most homes in my zip do sell for close to list price...which means it's not that high.

My home was appraised about a year ago (for a refinance) and the valuation was not even close to $515/sq ft. Closer to $375 sq ft.

Something is off, somewhere. I'm curious to know if anyone who has recently bought or sold has discovered what Zillow's margin of error is.
Did an appraiser physically come out and inspect your property? I ask because for my last two refis the bank didn't bother with an appraisal, they just went off of an internal bank estimating service. Since there was so much equity and no cash out it was simply an exercise in CYA.

Refis are notorious for being a little low.

As to Zillow's accuracy, our properties have all been a little unique and the Z estimate has fluctuated wildly. But I still value the data and use it as a starting point. As an example my Bay Area house has a Z estimate of about $1.2M. I know I can get at least $1.5 and probably more. Zillow is thinking that it's an overbuilt rancher (there are homes directly below mine which range from 1,000-1,400 sq.ft.). Those homes are not worth about $1M. While it throws us a bone for having 2,500 sq.ft. it can't estimate that we have a spectacular ocean and valley view and mostly flat lot. We're also going to spend a little money over the next couple of months so that we can correctly claim a 4br 3bth vs it's currently listed 3br 2.5bth.

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Just sayin...
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Re: How far off are Zillow's estimates?

Post by Just sayin... » Wed Aug 02, 2017 10:44 am

Over the course of the past two months, Zillow has valued my home +$100k and then down $250k (a $350k swing). They deleted the upwards swing on their site and zesstimate graph (erased their mistake?), but it was permanently captured in Personal Capital's wealth aggregator, so there's some proof. I consider Zillow's estimates to be beyond worthless - I believe they actually cause harm. Thankfully, I do not track my home value as part of my true net worth, nor base any of my retirement calcs on same.

JGoneRiding
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Re: How far off are Zillow's estimates?

Post by JGoneRiding » Wed Aug 02, 2017 10:56 am

avalpert wrote:I would suspect their 'median list price' is accurate since that is pulling from known data. There home value estimates are certainly off, my hunch is the factor is so volatile as to not be helpful.

As for your own appraisal - it should include both comps and detailed workup of the home itself so you should be able to get a sense for what separates your home from others.
No, it really depends on your house type. As stated within a development it is very accurate. If a lot of real estate is moving it is fairly accurate. If you have a custom built house on unique property with lots of variation in house types near by then its a complete guess.

Carefreeap
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Re: How far off are Zillow's estimates?

Post by Carefreeap » Wed Aug 02, 2017 10:59 am

Alan S. wrote:
Have a neighbor with a home with a shop on the lower level with attached bath. Owner changed Zillow input to call the shop a 4th bedroom and the zestimate immediately went up 40k. The owner changed nothing about this space other than the description. No one would want to have this space as their bedroom, so the reckoning will take place when he lists the home.
Most people who are looking for 4 bedroom homes aren't really looking for four bedrooms. Many are looking for a home office, in-law suite, studio or ? Is the property you are talking about in Prescott? Is it possible that area could be converted to a little rental unit or Air bnb unit?

We will be doing something similar although we are spending some money to get there. :wink: Our home is currently listed as a 2,500sq.ft. 3br 2.5bth. We have what some on the East Coast would call a walk-out basement in the lower level next to our garage. Our official entrance and main part of the house is actually on the second level. This ground level space will be separated from the laundry area and garage and has it's own separate entrance and patio area. Although it's a little dark for my taste (NW facing) it does have a pretty nice ocean and valley view. And at 700 sq.ft. could rent out for about $1,500/mth rent in our crazy Bay Area rental market.

While our plans for the space are actually for an entertainment "man-cave" I want to make sure this space is flexible for the next occupant. At a minimum it will be able to be called a 2500 4br 3bth which will increase its value in the general marketplace.

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Admiral
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Re: How far off are Zillow's estimates?

Post by Admiral » Wed Aug 02, 2017 11:07 am

OP here.

Our zip has a mix of historic homes (mine, circa 1850), loft conversions, very expensive larger homes that are new construction (3500-4500 sq ft, selling for 1.2-2.5 million), some 1980s townhomes, some apartments, etc.

So, this is probably part of the problem in terms of the median numbers they give.

I still don't understand why they don't post sold prices. Wouldn't this alone help them make their data more accurate?

Rupert
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Re: How far off are Zillow's estimates?

Post by Rupert » Wed Aug 02, 2017 11:13 am

bcdfgh wrote:My house is for sale and listed under mls. Zillow doesn't let me as a homeowner to correct the errors. I then contacted them requesting for correction but they ignored so I changed the status to sold for $1 hopping my listing wouldn't be shown there. I would rather have no listing there than have errors. The listing was gone for a few days then reappeared with the same errors. County record, Trulia, Redfin, Realtor.com and other sites show correct data.
I've corrected Zillow errors re the size of my home at least twice. You have to open an account and claim the home as yours, which is annoying, but it's possible. Why won't they let you do it?

avalpert
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Re: How far off are Zillow's estimates?

Post by avalpert » Wed Aug 02, 2017 11:19 am

JGoneRiding wrote:
avalpert wrote:I would suspect their 'median list price' is accurate since that is pulling from known data. There home value estimates are certainly off, my hunch is the factor is so volatile as to not be helpful.

As for your own appraisal - it should include both comps and detailed workup of the home itself so you should be able to get a sense for what separates your home from others.
No, it really depends on your house type. As stated within a development it is very accurate. If a lot of real estate is moving it is fairly accurate. If you have a custom built house on unique property with lots of variation in house types near by then its a complete guess.
I live on a cul-de-sac with ~40 nearly identical townhomes - Zillow was off on the last two sales by more than 10%. That isn't bad but I wouldn't call it very accurate.

dave_k
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Re: How far off are Zillow's estimates?

Post by dave_k » Wed Aug 02, 2017 11:41 am

Admiral wrote:I still don't understand why they don't post sold prices. Wouldn't this alone help them make their data more accurate?
They do have sale history data, at least in places I've looked. They show "recently sold" prices if you select that Listing Type. That's what I use to find my own comps.

hirlaw
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Re: How far off are Zillow's estimates?

Post by hirlaw » Wed Aug 02, 2017 11:43 am

How does Zillow do its estimate in states such as Texas, where the property sales price information is not publicly available?

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